Can I configure virtual wireless interface security setings?

Can I configure virtual wireless interface security setings to something different than the default wireless interface. I have a WNR3500L running Shibby 1.28 and want to set up aguest network. I created a virtual wireless interface with seperate SSID and I can connect from external computer. But I don't see anywhere in the configuration (browser) interface to set up the security parameters. Currently, it has no security.
Thanks.

Thanks darkknight93. I dont know how I missed that!
But I still have one problem: It will only let me select AP mode but I want to connect to an ad hoc network device. All of the other selections are greyed out.
Thanks.